Keeebs
Member
- Joined
- Feb 2, 2020
- Messages
- 20
Hello, I'm getting into reloading and finally thought I would reach out. My chrono arrived today, up until today I've loaded maybe 50 rounds before I realized I needed to know what my rounds where doing before I continued.
I used Hornady load data ( I have 1book1caliber, Layman and Lee books) But for the 1st chrono test I decided to start with manufacture load data.
I setup 3 batches to test low and work up.
My question is about sets 1 & 2, they are 260-300fps slower than data, Test data was with a 8" barrel and I understand the shorter barrel (6" in my gun) will be less FPS's than load data. But Set 3 is within 30 fps of published data. So basically is it normal to get 300fps less than published data on some loads and become very close to load data on other loads.
The only thing I can think of is Factory round benchmark, set 1 and set 2 heated up the barrel, and set 3 had an advantage. I plan to shoot set 3 on a cold gun tomorrow to see how it changes. The chrono makes reloading much more interesting.
Below is information I've gathered. Thanks!!!!
Gun:
.357 Mag
Ruger GP100 6" barrel
Factory Round Benchmark:
Federal American Eagle 158gr JSP
My loads:
Powder: 2400
Bullet: Hornady 38 CAL 158gr XTP (Part# 35750)
Primer: CCI 550 (Small pistol magnum)
Case length: 1.275-1.280 (I started with my shorter cases to save my "spec" cases for when I get closer to load development).
Powder Charges: (each case is zero'd and weighed after powered thrown)
Set 1: 10.5gr -10.6gr
Set 2: 11.4gr - 11.5gr
Set 3: 13.3gr - 13.4gr
Factory Benchmark 357: Federal American Eagle 158gr JSP
Temp: 55 °F
BP: 1022.00 inHG
Shots
# FPS FT-LBS PF
4 1224 0.00 0.00
3 1215 0.00 0.00
2 1260 0.00 0.00
1 1187 0.00 0.00
Average: 1221.50
StdDev: 30.12
Min: 1187
Max: 1260
Spread: 73
True MV: 1221.50
Shots/sec: 0.06
Group Size (IN): 0.00
Set: 1
Temp: 55 °F
BP: 1021.00 inHG
Shots
# FPS FT-LBS PF
6 724 0.00 0.00
5 822 0.00 0.00
4 783 0.00 0.00
3 824 0.00 0.00
2 615 0.00 0.00
1 670 0.00 0.00
Average: 739.67
StdDev: 85.33
Min: 615
Max: 824
Spread: 209
True MV: 739.67
Shots/sec: 0.06
Group Size (IN): 0.00
Set: 2
Temp: 55 °F
BP: 1021.00 inHG
Shots
# FPS FT-LBS PF
6 895 0.00 0.00
5 763 0.00 0.00
4 830 0.00 0.00
3 892 0.00 0.00
2 836 0.00 0.00
1 840 0.00 0.00
Average: 842.67
StdDev: 48.44
Min: 763
Max: 895
Spread: 132
True MV: 842.67
Shots/sec: 0.55
Group Size (IN): 0.00
Set: 3
Temp: 55 °F
BP: 1021.00 inHG
Shots
# FPS FT-LBS PF
6 1138 0.00 0.00
5 1142 0.00 0.00
4 1115 0.00 0.00
3 1144 0.00 0.00
2 1062 0.00 0.00
1 1113 0.00 0.00
Average: 1119.00
StdDev: 31.04
Min: 1062
Max: 1144
Spread: 82
True MV: 1119.00
Shots/sec: 0.55
Group Size (IN): 0.00
I used Hornady load data ( I have 1book1caliber, Layman and Lee books) But for the 1st chrono test I decided to start with manufacture load data.
I setup 3 batches to test low and work up.
My question is about sets 1 & 2, they are 260-300fps slower than data, Test data was with a 8" barrel and I understand the shorter barrel (6" in my gun) will be less FPS's than load data. But Set 3 is within 30 fps of published data. So basically is it normal to get 300fps less than published data on some loads and become very close to load data on other loads.
The only thing I can think of is Factory round benchmark, set 1 and set 2 heated up the barrel, and set 3 had an advantage. I plan to shoot set 3 on a cold gun tomorrow to see how it changes. The chrono makes reloading much more interesting.
Below is information I've gathered. Thanks!!!!
Gun:
.357 Mag
Ruger GP100 6" barrel
Factory Round Benchmark:
Federal American Eagle 158gr JSP
My loads:
Powder: 2400
Bullet: Hornady 38 CAL 158gr XTP (Part# 35750)
Primer: CCI 550 (Small pistol magnum)
Case length: 1.275-1.280 (I started with my shorter cases to save my "spec" cases for when I get closer to load development).
Powder Charges: (each case is zero'd and weighed after powered thrown)
Set 1: 10.5gr -10.6gr
Set 2: 11.4gr - 11.5gr
Set 3: 13.3gr - 13.4gr
Factory Benchmark 357: Federal American Eagle 158gr JSP
Temp: 55 °F
BP: 1022.00 inHG
Shots
# FPS FT-LBS PF
4 1224 0.00 0.00
3 1215 0.00 0.00
2 1260 0.00 0.00
1 1187 0.00 0.00
Average: 1221.50
StdDev: 30.12
Min: 1187
Max: 1260
Spread: 73
True MV: 1221.50
Shots/sec: 0.06
Group Size (IN): 0.00
Set: 1
Temp: 55 °F
BP: 1021.00 inHG
Shots
# FPS FT-LBS PF
6 724 0.00 0.00
5 822 0.00 0.00
4 783 0.00 0.00
3 824 0.00 0.00
2 615 0.00 0.00
1 670 0.00 0.00
Average: 739.67
StdDev: 85.33
Min: 615
Max: 824
Spread: 209
True MV: 739.67
Shots/sec: 0.06
Group Size (IN): 0.00
Set: 2
Temp: 55 °F
BP: 1021.00 inHG
Shots
# FPS FT-LBS PF
6 895 0.00 0.00
5 763 0.00 0.00
4 830 0.00 0.00
3 892 0.00 0.00
2 836 0.00 0.00
1 840 0.00 0.00
Average: 842.67
StdDev: 48.44
Min: 763
Max: 895
Spread: 132
True MV: 842.67
Shots/sec: 0.55
Group Size (IN): 0.00
Set: 3
Temp: 55 °F
BP: 1021.00 inHG
Shots
# FPS FT-LBS PF
6 1138 0.00 0.00
5 1142 0.00 0.00
4 1115 0.00 0.00
3 1144 0.00 0.00
2 1062 0.00 0.00
1 1113 0.00 0.00
Average: 1119.00
StdDev: 31.04
Min: 1062
Max: 1144
Spread: 82
True MV: 1119.00
Shots/sec: 0.55
Group Size (IN): 0.00